Dragons were huge, evil, scaled, and long-lived creatures of northern Middle-earth. Dragons were greedy, loved hoarding treasure, and could enchant or bewilder their enemies with their words and eyes.

Dragons were created by Morgoth in the First Age. He made three different types of Dragons, the Urulóki, the winged dragons, and the cold-drakes. Urulóki were dragons such as Glaurung, who could breathe fire, but could not fly. Winged dragons could both breathe fire and fly, and cold-drakes seemed to have been able to fly, but not breathe fire.

By the end of the Third Age, most dragons lived in the far north, in a part of a chain of moiuntains known as the Withered Heath. In 2770, Smaug set forth and took the Lonely Mountain, Erebor, but was slain in 2941.